1. Field of the Invention
This invention relates to medical instrument sterilization systems, and in particular to sterilization systems that utilize Ozone (O.sub.3) as the sterilizing agent and provide for humidifying a sterilizing agent flow.
2. Prior Art
While humidification technologies have long been employed in the field of medical instrument sterilization, and even systems utilizing ozone (O.sub.3) as the sterilization agent in such systems have previously been employed, and even some have provided for humidifying a flow of which sterilization agent. None, however, have provided for maintaining the relative humidity within the saturation curve of an ozone and oxygen gas mixture. Which saturation curve is the water vapor capacity of a mixture of oxygen and ozone gas at different variations in the gas mixture temperature, pressure, ozone concentration and gas flow rate. Unique to the present invention, the system controls water vapor content of a gas stream by monitoring its temperature, pressure and water vapor content utilizing thermistors and pressure transducers, along with a solid state humidity probe. A continual monitoring and adjustment establishes the precise water vapor content and delivery temperature of an ozone oxygen gas mixture at pressures which are requisite for sporicidal efficacy. The system of the invention provides for delivery of a stabilized oxygen-ozone gas mixture to even a remote container for sterilization usage, even when that gas flow is subjected to different environments as could alter flow conditions. Which water infusion is provided by a unique non peristaltic system of the invention which provides for incremental delivery of water to the vaporizer from a disposable vessel, thereby reducing any concern for cross contamination by elimination of standing water in the sterilization system.
The invention is preferably part of an ozone sterilization system that provides a separate containment system wherein the humidified ozone and oxygen mixture as a sterilizing agent is circulated to sterilize medical instruments. Which system provides for directing the humidified sterilization agent into a primary sterilization chamber that is separately sealed, is maintained within a second separate outer safety containment chamber, provides for monitoring conditions within both the primary sterilization and safety containment chambers, and is removable in its sealed state for transport. Though, of course, the invention is suitable for inclusion with another ozone sterilization system where a controlled gas humidification and disposable water delivery arrangement is appropriate.
Some examples of medical equipment sterilization systems that utilize heated ozone as the sterilization agent are shown in patents to Masuda, U.S. Pat. No. 5,120,512 and to Karlson, U.S. Pat. No. 5,069,880; and a plurality of container and chamber arrangements for use in sterilization processes utilizing treated ozone as the effluent are shown in patents to Anderson, et al, U.S. Pat. No. 5,118,471; and to Lutz, U.S. Pat. No. 5,087,419. None of which systems or arrangements provide for a precise gas conditions monitoring and appropriate water infusion from a disposable source to the gas flow to provide a precise water vapor content to maximize the sporicidal efficacy of the system.